he was right too often in a world where lies rule
it's the UK, they dont have free speech
There's absolutely no issue about free speech here.
He is free to say whatever he likes.
If you are a remember of a professional and regulated body you agree to adhering to certain standards, which he did not. Hence being struck off.
Similar to if you are a barrister and then start spouting sovereign citizen stuff. They will boot you as you are unfit for the organisation.